2. Second problem is related with previous one. From Infrastructure home page: when OVM manager is selected and from the menu if I click on: Administration->Storage, then the following error message appear: An error was encountered while attempting to get the Storage Servers list. Please see logs for detail.
In log file I found the following errors:

Caused by: oracle.sysman.vt.ovm.integration.api.EMOVMCommunicationServiceException: 5018: Error getting plugin information[com.oracle.ovm.mgr.api.exception.IllegalOperationException:OVMAPI_7271E Single access operation: "getAccessHost", is not allowed. The iSCSI storage array: SAN-ISCSI-MTX, has multiple access descriptors. [Tue May 21 17:04:18 CEST 2013]]
at oracle.sysman.vt.ovm.integration.core.StorageManagerImpl.getAllPlugins(StorageManagerImpl.java:148)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at oracle.sysman.vt.fetchlet.pojo.OVMDataFetchletUtil.executeOperation(OVMDataFetchletUtil.java:241)
at oracle.sysman.vt.fetchlet.pojo.OVMDataFetchletUtil.executeOperation(OVMDataFetchletUtil.java:120)
at oracle.sysman.vt.fetchlet.pojo.OVMDataFetchletUtil.executeOperation(OVMDataFetchletUtil.java:148)
at oracle.sysman.vt.fetchlet.pojo.OVMMMetricsData.getData(OVMMMetricsData.java:86)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at oracle.sysman.vt.fetchlet.impl.OVMMFetchlet.getMetric(OVMMFetchlet.java:91)
at oracle.sysman.gcagent.target.interaction.execution.FetchletFactory.getMetric(FetchletFactory.java:395)
at oracle.sysman.gcagent.target.interaction.execution.ExecuteTask.executeQueryDescriptor(ExecuteTask.java:1024)
at oracle.sysman.gcagent.target.interaction.execution.ExecuteTask.runTask(ExecuteTask.java:3826)
at oracle.sysman.gcagent.target.interaction.execution.ExecuteTask.call(ExecuteTask.java:4938)
at oracle.sysman.gcagent.target.interaction.execution.ExecuteTask.call(ExecuteTask.java:220)
at oracle.sysman.gcagent.task.ActionDriver.call(ActionDriver.java:57)
at oracle.sysman.gcagent.target.rowsource.TableRowSource._fetch_internal(TableRowSource.java:171)
at oracle.sysman.gcagent.target.rowsource.Rowsource._fetch(Rowsource.java:206)
at oracle.sysman.gcagent.target.rowsource.Rowsource.fetch(Rowsource.java:218)
at oracle.sysman.gcagent.target.interaction.execution.ExecuteTask.executeRSTree(ExecuteTask.java:3186)
at oracle.sysman.gcagent.target.interaction.execution.ExecuteTask.executeRSTree(ExecuteTask.java:3163)
at oracle.sysman.gcagent.target.interaction.execution.RTMCollection.getRTMRequest(RTMCollection.java:726)
at oracle.sysman.gcagent.target.interaction.execution.RTMCollection$RTMExecutor.call(RTMCollection.java:514)
at oracle.sysman.gcagent.target.interaction.execution.RTMCollection$RTMExecutor.call(RTMCollection.java:443)
at oracle.sysman.gcagent.task.DiagWrappedAction.call(DiagWrappedAction.java:52)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at oracle.sysman.gcagent.task.SingleActionTask.run(SingleActionTask.java:74)
at oracle.sysman.gcagent.task.AbstractTemplateTask.call(AbstractTemplateTask.java:185)
at oracle.sysman.gcagent.task.AbstractTemplateTask.call(AbstractTemplateTask.java:47)
at oracle.sysman.gcagent.task.executor.DiagWrappedTask.call(DiagWrappedTask.java:60)
at oracle.sysman.gcagent.task.TaskFutureImpl$WrappedTask.accountedCall(TaskFutureImpl.java:548)
at oracle.sysman.gcagent.task.TaskFutureImpl$WrappedTask.call(TaskFutureImpl.java:587)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at oracle.sysman.gcagent.task.TaskFutureImpl.run1(TaskFutureImpl.java:340)
at oracle.sysman.gcagent.task.TaskFutureImpl.run(TaskFutureImpl.java:305)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at oracle.sysman.gcagent.util.system.GCAThread$RunnableWrapper.run(GCAThread.java:141)
at java.lang.Thread.run(Thread.java:662)

If you are seeing errors when accessing the Administration->Storage page in EM, it may be because the Oracle VM Manager is down or you have not correctly registered it with EM.

You said you are able to deploy the VM from OVM Manager, so looks like the OVM Manager infrastructure is stable and up.

When using EM 12.1.0.2 (Release 2) for managing Oracle VM 3.2.2 environments, please make sure that you are using the latest EM Plug-in for Oracle Virtualization 12.1.0.4 and EM Plug-in for Oracle Cloud 12.1.0.5. Follow the My Oracle Support note 1371536.1 to update to the latest plug-ins and ensure that the required patches are applied.

All plug-ins are on suggested version. (EM Plug-in for Oracle Virtualization 12.1.0.4 and EM Plug-in for Oracle Cloud 12.1.0.5).
I missed the support note 1371536.1. So I will install all patches from note and then I will update this thread soon as possible.

I didn't know about this limitation of the EM VT plug-in 12.1.0.4.
In our scenario we are using EMC storage. This storage has two storage processors and each storage processor have two different network interfaces. In this case every LUN on storage is visible thru 4 paths. Accessing storage thru only one access server is not acceptable, single failure on storage processor or network can collapse entire infrastructure.
Any way this is just a test environment and we are in a process of evaluating of several virtualization and cloud software. I hope this problem in plug-in will be fixed.

I installed the newest version of EM 12.1.0.3 (VT plugin is 12.1.0.5.) and upgrade the OVM Manager to 3.2.3.

Now situation is better: I can access the repository storage page in EM, repository is fully managed (with previous version of plug-in managing repository was impossible), but problem with provisioning VT machine still remain. Provisioning job end with Failed status. In job log I found the following error:

Sorry, the company policy does not aloud me to do this. To aloud some one out of company to access local system I need to prepare special environment and plus tons of paper work (approval from security officer, managers).